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An anonymous reader writes "An electromagnetic 'black hole' that sucks in surrounding light has been built for the first time. The device, which works at microwave frequencies, may soon be extended to trap visible light, leading to an entirely new way of harvesting solar energy to generate electricity. A theoretical design for a table-top black hole to trap light was proposed in a paper published earlier this year by Evgenii Narimanov and Alexander Kildishev of Purdue University in West Lafayette, Indiana. Their idea was to mimic the properties of a cosmological black hole, whose intense gravity bends the surrounding space-time, causing any nearby matter or radiation to follow the warped space-time and spiral inwards."

It's a lens, specifically, that bends light into a spiral path that ends in the middle of the lens. It could presumably be used to amplify light into a small point. The same small point, regardless of the way the light strikes the surface of the lens, making it potentially useful for solid-state light gathering.

Apologies if you made this post without the aid of caffeine... or if you're quoting verbatim from Palin's blog (which I kinda doubted at first since it uses the words "cold fusion" but that COULD be some obscure Alaskan sexual practise)

FTA... In their device, the core converts the absorbed light into heat... So, it is be reradiated out the bottom/top of the cylinder. Just one more reason why you are right to call it a waveguide, albeit a very advanced one.

If they stop it's still an elephant in the room. Since this is never going to go away, I think I side with the idea of continual misuse of this term, thus encouraging a public view more akin to the boy who cried wolf. Once we get there, we can actually make the black hole that destroys earth, in peace.

Yes please, my first gut reaction was to say "holy crap, what could possibly go wrong?" Then I read the article and my reaction was, "holy crap, this is a revolutionary way of capturing electromagnetic waves that." Seriously, this seems from the super short non-descriptive article, like it could actually be on every solar panel in 10 years.

I completely agree, they need to fix the name lol. Although it is catchy, something like "light sucker" or something would make more sense.

Such a device could be used to harvest solar energy in places where the light is too diffuse for mirrors to concentrate it onto a solar cell. An optical black hole would suck it all in and direct it at a solar cell sitting at the core. "If that works, you will no longer require these huge parabolic mirrors to collect light," says Narimanov.

The article gives no indication that light passing near the device will get sucked into it, but only that all light hitting the device gets sucked into the center. So instead of requiring those huge parabolic mirrors, you'll instead require these huge cylindrical structures. Would still have a nice advantage in that no tracking or steering devices would be required since light hitting it from any side gets "sucked in", but it would still require a considerable amount of real estate to deploy assuming that they can both scale it down (to handle visible light) and scale it up (to make the amount of light absorbed represent a non-trivial amount of power).

It could well reduce the total light gathering area needed in low light conditions though. A typical solar cell is not a perfect black. Some fraction of the light reflects back. By capturing all of it you need a smaller area for the same effect. In addition, this could gather light omnidirectionally, a big benefit when the light is diffuse.

The article gives no indication that light passing near the device will get sucked into it, but only that all light hitting the device gets sucked into the center. So instead of requiring those huge parabolic mirrors, you'll instead require these huge cylindrical structures.

No, think about it. All light that intersects the volume of the device from any direction, vs. only light parallel to the optical axis and incident on the concave side of the mirror. It's obvious that this device will collect a lot mo

This could easily be the next smoke rounds. Imagine being able to block light past specific points on a battlefield. You could effectively blind the enemy in darkness, or create soft cover for your movements. It would also absorb laser tracking and targeting devices, leaving many modern weapons systems moot.

Make no mistake about it, this is a very important technology for the battle field.

... it founders on the usual issue - cost effectiveness. Smoke rounds already do this job very well, and they're bound to be a lot cheaper. They're also a lot easier to emplace (can you imagine firing one of these "black hole" deals out of an artillery piece, and having it get to its destination intact?). I wouldn't hold my breath waiting for this to show up on the battlefield.

Except for the fact that these are cylindrical solid structures and are definitely not going to be shrunk down to aerosol particle size. You're not going to get these deployed less conspicuously than a portable wall that has been painted black.

The materials they use for this are useful for the military, which everyone agreed on when they were first discovered.

Narimanov and Kildishev reasoned that it should be possible to build a device that makes light curve inwards towards its centre in a similar way. They calculated that this could be done by a cylindrical structure consisting of a central core surrounded by a shell of concentric rings.

Article in the current issue of Air and Space magazine [airspacemag.com] about this sort of technology and how might be used to create cloaking devices one day.

Scientists and engineers are trying to emulate that trick by designing materials that could constitute the next-next (or next-next-next) generation of stealth. Some of their ideas sound like they sprang from the imaginations of Gene Roddenberry or J.K. Rowling, with phrases like “cloaking device” and “invisibility carpet” popping up as freque

Make tiny black holes with an event horizon of say 1 foot. Then we have the ultimate trashcan. We can dump nuclear wast in it and nothing will come out except for perhaps according to some theories radiation. Which we cannot see or feel so there forth it must be harmless.

The Chinese paper refers to effectiveness at 18GHz, which just so happens to be in the "K" band of radar frequencies. You know, the one police like to use.

So all these guys need to do is make a dashboard- or grille-mounted radar absorber to obsolete the radar detector and they'll be so rich they'll forget their ultimate goal of destroying the world or whatever.

Except that many police forces are using lasers instead of radar to detect speed now.

And if you want to use something similar to be invisible to a laser, you might just end up being invisible (depending on the laser frequencies you absorb). Which would be pretty darked cool, except when traffic doesn't see you at night.

As far as I understand, given that there's no invisibility cloaks working for those frequency and that this is a variation on these device, I doubt the experimenter's claim that they'll be able to build an optical black hole soon..

How much energy does it "take?"
Its a metamaterial structure, and the refractive properties are caused by its shape alone.

That said, all that incident EM radiation is gonna really heat it up... so if you were going to put a solar panel in the middle, as the article describes, then it will likely require cooling if its placed in bright conditions.

Unless they're very clever with creating it, such that only wavelengths usable by the solar panel are refracted into the centre. Anyway, if they think they can do that by the end of 2009, can they make me a man-sized invisible hamsterball? Invisible zorbing would be an interesting experience.

I don't know why a huge amount of a nano-structured meta-material would be cheaper to make than a large mirror. The device is interesting in it's own right but the application to solar power is a real stretch. It seems like every advance has to claim to be a step on the way to curing cancer or solving the energy crisis to get any attention. Even the article about magnetic monopole quasi-particles tied it back to applications to computing...possible but that certainly isn't why the discovery is interesting.

It seems tremendously unlikely that this thing would be cheaper than what it aims to replace. There could possibly be a use for it in certain unusual situations - say, providing solar power to a spacecraft in the outer solar system. You might be able to get sufficient power without having to loft a giant mirror into space. But even in this case, it seems like the standard radiothermal generators would be a better choice.

I doubt it would be cheaper to make, but a mirror reflects light from one direction and if you have concave shape focuses that light at a certain point, but for that to work the light has to be entering from the right direction relative to the focus point (normal straight in the front but doesn't necessarily have to be

This system would work regardless of which direction the light enters from, which means it works under very difuse light source. It also means you don't need a tracking system to keep the mirr

Agreed. I came back to read the comments because I had this same though. The article says they could replace the huge parabolic mirrors used in solar collection. So they want to replace a large mirror, with a large fuunnel made of obscure expensive materials? How does that help?

It replaces the large, parabolic mirror which has a bunch of steering gear with a large, metamaterial collector that requires none. It makes the whole system a lot more "install and forget", removing the maintenance, moving parts, etc. It would also work well for smaller scale installations, and for installations that don't face directly at the sun (north facing, etc.). It would work well on cloudy days, indoors, and in a host of situations that a parabolic focusing arrangement would be impractical or usele

Problem is, some of us can see right through those...
Those of us that do IT support for friends & family know that Someone Else's Problems have a nasty habit of becoming Our problems at a moment's notice.

It uses no energy once it's built as far as I can tell. It takes a series of materials that guides light (or electromagnetic radiation not in visible spectrum yet) and directs it into the center of the device which turns it into...well, currently heat. In a while when they get the visible light spectrum version working they will probably have the core be a solar panel so they can turn light into electricity.

Interesting culture you've got there. Where I work the theorists/computational groups find the experimentalists indispensible and vice versa. The experimentalists provide the grounding in reality and provide the final fruition of all the theory/computer work. The theory+computation guides the experiments and increases the odds that the experiments'll work the first time out. Everyone's better off, and everyone knows it, with the exception of just one guy who's generally hard to deal with anyway (even the other experimentalists don't get on with him.)

The device sounds interesting but the reporter's notion of gravity is utter nonsense.

Huh? The description you quote seems like a pretty reasonable qualitative description of an astrophysical black hole to me. Black holes have a region of capture orbits [fourmilab.ch] outside the horizon, where nearby matter spirals inwards.

Not that astrophysical black holes have anything whatsoever to do with the electromagnetic devices referred to in the article, of course.

Only the portion of the bursts that actually hit the device. The "Event horizon" here is limited to the device's physical size. I guess you could hide behind it if you know the burst is coming and its direction...